This invention relates to internal combustion engines, and is particularly directed to a miniature internal combustion engine in which the fuel for the engine is directed to the engine through a hollow crankshaft.
Internal combustion engines having a fuel inlet suction passageway extending through the crankshaft are as such known. German Offenlegungsschrift No. 1,526,345 discloses a single cylinder, two piston Otto or Diesel four cycle motor, in which the connecting rod extends into the crank housing. In this arrangement, the work energy is transferred from the piston to the fly wheel by way of the connecting rod and the crankshaft. This arrangement is not well adapted for use as a miniature motor.
A construction for an internal combustion engine has long been sought, which enables the smallest possible size of the engine, but yet is sufficiently variable that the same principles may be employed as in the construction of larger engines. It is thus desirable to provide an engine which may be employed in toys, such as model airplanes, and model ships, but which may also be constructed in larger size, for example, for use in lawn mowers and even in vehicles.
German Offenlegungsschrift No. 2,117,207 discloses an internal combustion engine having two cylinders arranged in a housing. This arrangement requires, however, the provision of two drive means for the pistons. As a consequence, the engine of this reference cannot be designed to have the least possible overall size.
In further known arrangements, the transmission of force from the piston is accomplished without any crankshaft. For example, German Offenlegungsschrift No. 1,576,043 as well as German Offenlegungsschrift No. 2,015,165 disclose arrangements in which the cylinder pistons are cyclically controlled by a grooved roller and a ball guided therein. In a somewhat similar manner, the force is transferred without any crankshaft by way of a ball guided in a wave shaped groove in the cylinder. This type of construction results in quite compact engines but the number of elements is high, and the size of such engines is still greater than desired.